From: Stanislav Fomichev sdf@google.com
commit e4f07120210a1794c1f1ae64d209a2fbc7bd2682 upstream.
Commit 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec") added invocations of btf_type_is_resolve_source_only before btf_type_nosize_or_null which checks for the NULL pointer. Swap the order of btf_type_nosize_or_null and btf_type_is_resolve_source_only to make sure the do the NULL pointer check first.
Fixes: 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Stanislav Fomichev sdf@google.com Acked-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/bpf/btf.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1928,8 +1928,8 @@ static int btf_array_resolve(struct btf_ /* Check array->index_type */ index_type_id = array->index_type; index_type = btf_type_by_id(btf, index_type_id); - if (btf_type_is_resolve_source_only(index_type) || - btf_type_nosize_or_null(index_type)) { + if (btf_type_nosize_or_null(index_type) || + btf_type_is_resolve_source_only(index_type)) { btf_verifier_log_type(env, v->t, "Invalid index"); return -EINVAL; } @@ -1948,8 +1948,8 @@ static int btf_array_resolve(struct btf_ /* Check array->type */ elem_type_id = array->type; elem_type = btf_type_by_id(btf, elem_type_id); - if (btf_type_is_resolve_source_only(elem_type) || - btf_type_nosize_or_null(elem_type)) { + if (btf_type_nosize_or_null(elem_type) || + btf_type_is_resolve_source_only(elem_type)) { btf_verifier_log_type(env, v->t, "Invalid elem"); return -EINVAL; @@ -2170,8 +2170,8 @@ static int btf_struct_resolve(struct btf const struct btf_type *member_type = btf_type_by_id(env->btf, member_type_id);
- if (btf_type_is_resolve_source_only(member_type) || - btf_type_nosize_or_null(member_type)) { + if (btf_type_nosize_or_null(member_type) || + btf_type_is_resolve_source_only(member_type)) { btf_verifier_log_member(env, v->t, member, "Invalid member"); return -EINVAL;